@charset "UTF-8";
.note {
  position: relative;
  background: #58a;
  /* 回退样式 */
  background: linear-gradient(-140deg, transparent 2em, #58a 0);
  border-radius: .5em;
}

.note::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  background: linear-gradient(to left bottom, transparent 50%, rgba(0, 0, 0, 0.2) 0, rgba(0, 0, 0, 0.4)) 100% 0 no-repeat;
  width: 2em/cos(40deg);
  height: 2em/sin(40deg);
  transform: translateY(2em/cos(40deg)-2em/sin(40deg)) rotate(-10deg);
  transform-origin: bottom right;
  border-bottom-left-radius: inherit;
  box-shadow: -0.2em 0.2em 0.3em -0.1em rgba(0, 0, 0, 0.2);
}
